I am rebuilding a 305 for my 92 Firebird. I was told that if I put to many performance parts on that my ECM will not function properly. Can I get an aftermarket chip, or reprogram it myself with a notebook PC, or should I go ahead and carburate it? If I carburate it what parts do I need to get the transmission to work correctly(OD at highway speed)? If tweaking the ECM with a PC will work, does anybody know where I can get a Serial or USB adapter for the diag. port? Thanks.

 

Hey welcome aboard. The key to making power with these cars lies in the ability to burn your own chips. You can have all the chip burning quiptment for around 200 to 400 bucks. This is the best place to start to familiarize yourself with the PROM work that is necessary when adding extensive mods. Check out the stikcies above for links on chip burning stuff. You will find most of your answers with a few searches in the DIY PROM board.

 

I'd also suggest not to rebuild a 305. I see that as a waste of money, if you're going to do a rebuild on an engine, do it on a 350. Would end up costing the same.

 

I was just reading those posts for the last half hour. Some good info in there. If I go with the method of reprogramming the EPROM will I be able to use the more aggressive camshaft that I wanted? Will I be able to compensate for all of the performance parts? What model of programmer do you reccomend? Thanks.

 

What are the specs on the more aggressive cam? Check out moates.net the flash-n-burn hardware is good as well as the Autoprom or the Prominator from another site. All good hardware. Might want to get your feet wet with the tuning before you jump into an engine with an aggressive cam though.

 

I hear you. It is a lot to learn all at once. Being a computer programmer never seems to help much with these things either. I kind of want to get the performance parts now because my engine is in parts setting on my bench. I am just getting ready to purchase my pistons and send them out with the block to be bored .030 over. I have been trying to study about my car/engine for a couple of weeks now. I am getting to that point where I am like f#$% it, I will buy performance parts and if it doesn't work I will rewire the whole thing and carb it, even though that isn't a very good way to approach it. . I know what I need to do to get HP out of this thing I just don't know how to keep the ECM working. Let me know if you have any more ideas about what PC equipment I will need. Thanks guys!

 

Well what kind of heads and cam are you looking at for it? I can tell you if it'll be computer friendly or not and how difficult to tune it'll be.

 

If its not too late, take all the pieces and send them off to be melted down and turned into something more useful. While the 305 is an ok motor, you can get more displacement and larger bores for the same cost. Its perfectly acceptable to mod a 305, but once it needs rebuilding then its time to look at getting a 350 or some variant of it.

 

I think I am going to keep this engine computer compatable and start looking for a 5-speed 350 F-Body. I want the most performance I can get and still not have to do too much with the computer. How high of duration can I go on the cam? Here are a couple I am looking at.

12-411-8: HYDRAULIC ROLLER: Good mid0range power, good performance increase. Largest with stock converter. Duration at .050: 210
Intake Valve Lift: 0.474
Exhaust Valve Lift: 0.474
Lobe Seperation: 111°

12-412-8: HYDRAULIC ROLLER: Mild performance applications, very good mid range, 3.23 -3.73 gears. Duration at .050: 212
Intake Valve Lift: 0.487
Exhaust Valve Lift: 0.495
Lobe Seperation: 110°

12-420-8: HYDRAULIC ROLLER: Mild street performance, slightly noticeable lope at idle. Stock converter, aftermarket intake and headers. 3.40 to 4.10 rear gears. Duration at .050: 215
Intake Valve Lift: 0.5
Exhaust Valve Lift: 0.5
Lobe Seperation: 110°

Thanks

 

You gotta keep in mind they never made a 5 speed with a 350, you can swap a 350 into a 5 speed car or get a 350 car and swap in a 5 (or idealy a 6) speed transmission. 110 LSA is low for a computer controlled car, look for one with a 112 or 114 LSA to make tuning easier.

 

You are wasting your time, theres no such thing as computer compatible, you need to tune for any modifications. If you want a fast car and dont want to mess with doing chips get a carburetor and build up a 350 however your financial situation permits

rebuilding a 305 does not make much sense at all but i dont forsee you changing your mind. Sometimes you just have to learn from experience.

 

I don't want to put a 5-speed into a car with an auto, so I am going to try to do what I can with this car and give it to my mom and start lookiong for a manual. My question is what is the best cam I can put into a 305? I also need to know what the best way to tune this comp will be. If anyone has some insight into this pleae let me know. Thanks again guys.